During the process of making steel, many residues are produced. Among these residues is sludge from basic oxygen converters. In converter-based steelmaking, high-velocity oxygen is injected into a basic oxygen converter, which is typically charged with molten pig iron, scrap metals, lime, and iron ore, in order to remove carbon and silicon from the charge and to form molten steel. This process produces a large volume of hot fumes that contain fine particles of the charge materials and carbon monoxide gas. To avoid polluting the environment, the hot fumes are scrubbed before being discharged into the environment. Typically, the fumes are quenched with water and cleaned of suspended metal particles and other solids. The remaining gas (carbon monoxide) is drawn off and is often used as fuel in the steelmaking process. The solids and the quenching water form a sludge that is collected, typically in a settling tank. This residue sludge, which comprises metallic iron particles and other solids, is generally separated into “thick” and “thin” sludges. The thick sludge contains the larger solids from the fumes and is usually either discarded into landfills or dried and used as sinter feed for blast furnaces that produces pig iron.